As someone that spends money, the problem with the event is that I'm lazy and don't want to mess with finding the casino, and that everything I get will be used as fodder in future casinos and so won't provide a return on investment, when I choose to sell the excess at a later date in time. My idea to fix this are as follows-
A) Casino stays on always, but is far more rare. Except during other events, where the slot needs filling with say... a certain punkin king.
B) The clockwork casino is limited to just the node slime gear, and gives out more crowns than anything. It's for casuals.
C) The event makes casinos spawn more frequently, and provides a daily link to the casino, so that gambling can be facilitated.
D) An event only slot that costs 50 to 100 slime coins and gives nothing but varying slime boxes and rarely whammies. Basically-
60% = good box; E.G. 40G = chance of hunter box etc.
20% = old box; I.E. From the last promo, but never further back than that
10% = best box; E.G. Hunter prize box, the new box directly
10% = Whammie!; Because it's unfair and kind of funny.